/Engine/Plugins/Online/OnlineServices/Source/OnlineServicesInterface/Public/Online/Auth.h
Token used during Login operation. The data provided as the credentials token varies based on the type of login being performed.
typedef [TVariant](API\Runtime\Core\Misc\TVariant)< [FString](API\Runtime\Core\Containers\FString), [FExternalAuthToken](API\Plugins\OnlineServicesInterface\Online\FExternalAuthToken) > FCredentialsToken